A retrospective descriptive study of oral diseases among children and adolescents aged 0-19 was accomplished from biopsy records of Dental School Oral Pathology Service, Universidad de la República, Uruguay, from 1982 to 2002. Out of 5301 biopsy cases, 746 corresponded to the proposed age range (14%). Lesions were divided into three groups: intraosseous (54.6%), extraosseous (43%) and dental diseases (2.4%). The radicular cysts, the tumors and the pseudotumors of the oral mucosa were the most frecuent osteogenic lesion (28.6). Malignant tumors constituted 0.4% of the cases. In summary, within the range of age considered, a higher frecuency of non-neo-plastic benign lesions was found